Integrated liquid-core optical fibers --- ultra-efficient nonlinear liquid photonics

TL;DR

This paper introduces a fully integrated liquid core optical fiber platform that enables ultra-efficient nonlinear liquid photonics, demonstrated by ultralow threshold Raman generation with potential applications in various nonlinear optical processes.

Contribution

The authors developed a practical, fusion-spliced liquid core optical fiber platform that significantly enhances nonlinear optical performance using liquids with high nonlinearities.

Findings

Achieved ultralow threshold Raman generation at ~1nJ energy

Demonstrated integration of liquid core fiber with standard fibers

Enabled new possibilities for low-power nonlinear optical applications

Abstract

We have developed a novel integrated platform for liquid photonics based on liquid core optical fiber (LCOF). The platform is created by fusion splicing liquid core optical fiber to standard single-mode optical fiber making it fully integrated and practical - a major challenge that has greatly hindered progress in liquid-photonic applications. As an example, we report here the realization of ultralow threshold Raman generation using an integrated CS2 filled LCOF pumped with sub-nanosecond pulses at 1064nm and 532nm. The measured energy threshold for the Stokes generation is ~ 1nJ, about three orders of magnitude lower than previously reported values in the literature for hydrogen gas. The integrated LCOF platform opens up new possibilities for ultralow power nonlinear optics such as efficient white light generation for displays, mid-IR generation, slow light generation, parametric amplification, all-optical switching and wavelength conversion using liquids that have orders of magnitude larger optical nonlinearities compared with silica glass.